Invalid command 'AuthDigestFile', perhaps misspelled or defined by a module not included in the server configuration
This error message is likely to appear, if you are using Apache 2.2, and are still using AuthDigestFile in your config file.
You should be using AuthUserFile instead. This only applies if you are using Apache 2.2.
<Location /private/> AuthType Digest AuthName "private area" AuthDigestDomain /private/ http://mirror.my.dom/private2/ AuthDigestProvider file AuthUserFile /web/auth/.digest_pw Require valid-user </Location>